Just 70 minutes after State Sen. Brian Birdwell announced his retirement Monday, Rep. David Cook declared his candidacy for the soon-to-be-open seat in Texas Senate District 22.

Birdwell (R-Granbury), a decorated Army veteran and 9/11 Pentagon survivor, made his retirement public in a heartfelt letter to constituents and a tweet that read, “It has been the high honor of my life, on par with commanding United States soldiers, to serve my fellow Texans for over 15 years.”

 

In the attached letter, Birdwell wrote, “I made clear I was not elected to a position of authority over the citizens of District 22, but rather elected to a position subordinate to them so that I could steward their seat in the State Senate.”

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He credited his Lord and Savior, Jesus Christ, his wife, Mel, staff, and constituents for their roles in his tenure.

“During my time in the Senate, we affirmed that Texas is a sanctuary for the unborn, expanded Second Amendment freedoms, banned woke insanity such as ESG and DEI… and prevented significant amounts of bad legislation from reaching the Senate floor.”

Birdwell, who was first elected in a 2010 special election, said he would not seek another term but would serve through the end of his current term.

Just over an hour later, Rep. David Cook (R-Mansfield) announced he would run to succeed Birdwell.

“Senator Birdwell is the personification of a servant leader, in both word and deed,” Cook said in a press release. “I am stepping forward because these challenges require experience, follow-through, and the time necessary to commit fully to the work ahead.”

 

Cook is currently serving his third term representing House District 96 and is a former mayor of Mansfield.

A practicing attorney, Cook is the managing partner of Harris Cook LLP, per his firm bio. His announcement praised Birdwell’s legacy while pivoting quickly to campaign messaging: “While we’ve accomplished a great deal, there’s more work to be done!”

Cook enters the race at a time of significant realignment within Texas’s GOP. He emerged as a central figure in the party’s ongoing internal power struggle, especially during the brutal 2025 speaker’s race, where he represented the party’s insurgent wing. He ultimately lost that race to Rep. Dustin Burrows (R-Lubbock).

Despite his loss in the House speaker race, Cook’s name recognition and close alignment with top figures—including Lt. Gov. Dan Patrick, who supported Cook’s speakership bid—may make him a formidable contender in SD-22.

The district is firmly Republican, encompassing parts of Central Texas, including cities like Waco, Cleburne, and Granbury.